Solved

How to set up environment for Python in cron?

Posted on 2010-11-09
6
1,185 Views
Last Modified: 2012-05-10
I have a Python script that runs fine standalone. When I add it to the cron on a Solaris, it fails. From the output log, the problem is it cannot find the PATH and LID_LIBRARY_PATH of the executable embedded in the Python. My question is how to set this up? Should this be done in the Python or in the cron? I have tried various ways without success. Here are two examples:

02 * * * * /home/<user>/test.py input1 > /tmp/test.log 2>&1
02 * * * * SHELL=/usr/bin/bash; export SHELL; . $HOME/.profile_user; /home/<user>/test.py input1 > /tmp/test.log 2>&1

Basically the Python runs with one input parameter. In the Python script, it calls a 3rd party executable. I see two env variable scripts I need to run - one is the .profile_user and another one is the app specific env.

Many thanks!
0
Comment
Question by:eduliu
  • 3
  • 2
6 Comments
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 34096937
Simplest way would be running the script from root's crontab as the "normal" user with "su -", so that the full environment of that user will be initialized.

02 * * * * su - normal_user -c "/home/<user>/test.py input1 > /tmp/test.log 2>&1"

wmp
0
 

Author Comment

by:eduliu
ID: 34097024
I just tried, but it didn't work - it didn't run. I guess it's becuase I'm not running cron as root. The account I use can create cron but under my account I assume. Any other way to insert a couple of scripts to set up the environment? Thanks!
0
 
LVL 16

Expert Comment

by:gelonida
ID: 34100058
if you want to call 3rd party executables, then it is enough to set the PATH variable from within python before you call your executable.


Alternatively you can create a wrapper shell script setting up the env before calling your python script.

import os
os.environ['PATH'] = 'newpath:' + os.environ['PATH']
os.environ['LD_LIBRARY_PATH'] = 'newpath:' + os.environ['LD_LIBRARY_PATH']
0
ScreenConnect 6.0 Free Trial

Check out the updates in one game-changing release, ScreenConnect 6.0, based on partner feedback. New features include a redesigned UI that improves session organization and overall user experience. See the enhancements for yourself!

 
LVL 16

Expert Comment

by:gelonida
ID: 34100068
the wrapper script solution would be:

#!/bin/sh
export PATH="newpath:$PATH"
export LD_LIBRARY_PATH="newpath:$LD_LIBRARY_PATH"

mypythonscript "$@"


0
 
LVL 16

Accepted Solution

by:
gelonida earned 500 total points
ID: 34100091
Third way is to set the vars directly in the crontab entry:


PATH=/usr/bin:mypath LD_LIBRARY_PATH=/usr/bin:mypath  /home/<user>/test.py input1


Please note.
no semicolons and no export statementments.

In all three cases you must be sure to add ALL required directories and all required environment variables, that are needed
for your third party executable to be run.
As I don't knowit you might have to experiment
0
 

Author Comment

by:eduliu
ID: 34102669
Thank you so much for the detailed and various options. Quite embarrassing, the cause was one variable in one of the env scripts had a value assigned wrong. Things are working now. Appreciate the help!
0

Featured Post

Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

FreeBSD on EC2 FreeBSD (https://www.freebsd.org) is a robust Unix-like operating system that has been around for many years. FreeBSD is available on Amazon EC2 through Amazon Machine Images (AMIs) provided by FreeBSD developer and security office…
Every server (virtual or physical) needs a console: and the console can be provided through hardware directly connected, software for remote connections, local connections, through a KVM, etc. This document explains the different types of consol…
Learn the basics of modules and packages in Python. Every Python file is a module, ending in the suffix: .py: Modules are a collection of functions and variables.: Packages are a collection of modules.: Module functions and variables are accessed us…
In a previous video, we went over how to export a DynamoDB table into Amazon S3.  In this video, we show how to load the export from S3 into a DynamoDB table.

773 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question